PROJECT SUMMARY/ABSTRACT ?Dementia Determinants in Caribbean and U.S. Hispanic Populations? This proposal in response to PAR-17-470 will significantly expand knowledge regarding dementia determinants and consequences in Caribbean-origin populations. We build on the 10/66 Dementia Research Group?s internationally harmonized surveys in capital city metro areas of Puerto Rico, Dominican Republic, and Cuba; these three islands/countries are the origin of the vast majority of Caribbean immigrants to the U.S. We will compare these data with the U.S. Health and Retirement Study, and particularly its Healthy Cognitive Aging Project (HCAP) sub-study which was designed for such international comparisons of dementia. 10/66 data indicate a remarkably high dementia prevalence of 10-12% among adults ages 65+ in these three Caribbean sites, whose similar histories but richly varying societal structures over the past century offer great promise for better understanding dementia in Caribbean-origin immigrant populations. Our international collaborative team will focus on three specific aims: (1) Collect new baseline survey data in non-metro Puerto Rico and Dominican Republic that parallel existing 10/66 samples from capital city areas, to better capture the variation in lifecourse exposures in these sending islands/countries. (2) Analyze dementia relationships with hypothesized lifecourse socioeconomic determinants across contexts, exploiting comparisons across vastly heterogeneous life circumstances to both understand drivers of dementia prevalence and to simulate how prevalence could plausibly be different under altered social circumstances. (3) Analyze the comparative societal costs of dementia (including both formal and informal care) to simulate how these costs could plausibly be different under altered societal arrangements.